Landscape Evaluations

Fourth Section in Litton's Article: Descriptive Approaches to Landscape Analysis

Landscape Evaluations:

Litton suggests that there are two kinds of evaluations in visual inventorying: professional judgment and the perceptions of the public.  In the first evaluation, the criteria used for professional judgments by landscape architects and environmental planners are essentially derived from design.  Written guidelines include the Visual Management System (USFS 1974) and the Visual Resource Management guides (USBLM 1976).  Both documents outline the fundamental ideas of “line, form, color, and texture as criteria; but they are exemplified but occurrences and relationships found in nature” (pg. 81).  Litton’s preference has been the aesthetic criteria of vividness, unity, form, space, color, and variety (1972), but he has tied these abstract terms to landscapes that express these values in tangible ways.  

•  Line – edge, silhouette, or contour
• Form – space and shape
• Color – hue, chroma, brilliance, and value
• Texture – part of surface variance and patterns

These visual assessment associate aesthetic criteria terms with basic physical elements of visual landscape (vegetation, landforms, water, and land use patterns) to create assessments of the landscape that clear to the observer.  The author also describes how “the sequential movement of an observer through the landscape, both in time and space, may profoundly alter a person’s sense of scenic values” (81).  

Visual inventory units are intended to reveal the characteristics of a landscape within its regional context.  Not only are these units part of an inventory, but they are essential in creating “comparative qualitative assessments among units” (pg. 81).  By viewing the landscape in “more tangible” units and sub-units instead of as a whole, it allows the observer and the professional to create a more detailed description and assessment of the landscape.  Litton explains that overall, the landscape evaluation is a sum of all the tangible units that emerge in a whole area.  He adds even though professional evaluations are primarily qualitative judgments; they still have quantitative procedures that must be applied.

• Qualitative judgments – “express the results of using criteria which are not themselves readily reduced to simple or precise numerical values” (pg. 81).

•  Quantitative procedures – applied to different visual units, these procedures can “systematically measure such things as relative relief, mosaic unit areas of various vegetation types, or numbers and coverage of water bodies” (pg. 81). 

The results from these measurements and assessments are useful in creating systematic comparisons between differing components in different units, however the ranking of their visual value still demands qualitative judgment.

Litton explains that “community participation in identification of perceived values of the landscape requires psychological or sociological analysis” (pg. 82).  However, he acknowledges that “Because of conflicting political views and administrative/legal restrictions, it is virtually impossible for public agencies to conduct social response studies on public land” (pg. 82).  Consequently, most public agencies use academic research as insight.  The author explains how workshops conducted by the National Park Service in 1978 revealed that preferences are generalized judgments that include “a complex of variables in which visual elements are elusive” (pg. 82).  Litton notes that more work is needed to develop workshops that better correlate physical-visual landscape criteria utilized by professionals with perceptual values identified by the public.  

Even with local values described in research and participatory evaluations, current opinions about landscape values should not restrict or solely dictate future landscape choices.  The author argues that “after evaluations are made, whatever their origin, the question remains about what decisions are most appropriate for landscape units of different value.  Where high quality is identified –as it is apt to be a rare thing – it is clear enough that special planning and design efforts  are called for…Otherwise the landscape falls apart, losing overall aesthetic quality” (pg. 82).  Litton believes that even though appropriate management should be given to regionally typical landscapes, special attention must be given to protect the landscapes that exhibit the highest level of regional scenic beauty and characteristics.

Landscape Evaluations applied to Vistas:

Vistas, like many landscapes, are affected by time and space.  Examples of this are viewing the landscape as you transcend from one forest type to the next; associating color and texture changes to the seasonal aspects of the landscape; and revealing how sunlight effects the observer’s impressions of the landscape as it shifts between sunrise to sunset.  Many of the Park’s vistas display extraordinary examples of the scenic quality that can be found in this region. 

Vistas are fundamentally “units”, revealing the relationships between both atypical and typical elements for the enjoyment of the observer.  Like most landscape evaluations, vista evaluations systematically rate the scenic quality of each view.  The evaluations used the criteria mentioned above to determine the elements’ visual values and relationships within each vista.  Even though public agencies rely heavily on professional landscape criteria, Park staff was still very receptive to visitor comments regarding improvements they wanted to see along vistas.  Numerous requests have been made to restore the view to the way it was intended to be.  Visitors who remember the vistas as they were decades ago would like their family to be able to see the same magnificent landscape they once saw.  However, landscapes conditions that were desirable in the past are not always compatible with present or future Park landscapes.  With these ideas in mind, Park staff assembled a team to determine a vista management plan.

After conducting a visual inventory and evaluation, the team surmised that there are 34 vistas that should be initially reopened to restore the most important iconic views.  This rating system incorporated qualitative judgments from the evaluation and allowed the Park to prioritize vista management by assigning a view rating of “A” (most significant), “B” (significant), or “C” (least significant) for each vista.  Vistas with the “A” rating exhibited a strong aesthetic relationship between natural elements, characteristically offering views of one or more significant elements.  Vistas with a “B” rating traditionally offered views of a range of typical elements with the occasional atypical element.  Vista with a “C” rating display typical elements that represent common ecosystems in the Park.  “A” and “B” rated vistas are meant to be viewed from a set point, while “C” rated vistas that are intended to be viewed while driving.  Adequate planning is necessary to preserve the visual integrity and protection of these iconic landscapes for enjoyment present and future generations.